Tower packing

ABSTRACT

A tower packing unit comprising a saddle-shaped platform having a circular edge in plan view and having hollow, slotted, turretlike projections extending up and down on each side of the platform. Slotted buttress vanes standing up and down on each side of the platform in chordal planes of said edge reach radially from each turret to the periphery of the platform. These vanes extend substantially the height of the turrets above the platform and extend in opposite directions from the turrets on the same side of the platform. The platform has openings to the turrets and to the slots in the vanes. The hollow turrets are slotted longitudinally and are of truncated conical form based on the platform. Preferably, there is a pair of such turrets extending away from each side of the platform with an interconnecting vane joining each pair of turrets in the center of the unit on each side of the platform. These vanes rise from opposite sides of the middle of the platform and lie in planes which contain the longitudinal axis of the unit and lie at right angles to each other.

United States Patent [72] Inventor Frederick W. Arndt Maspac. Publication of Saran Lined Pipe Co., Ferndale,

Bay Village, Ohio Mich. Received July 26, i966. 880,844

[ Appl- Primar E T R M l y .tammerlm l es [22] Med May 1969 Attorney-Bosworth, Sessions, Herrstrom and Cain [45] Patented Nov. 9, 1971 [73] Assignee Hell Process Equipment Corporation Cleveland, Ohio shaped platform having turretlike projections extending up and ess vanes ing up and down on each side of the platform in chordal y from each turret to the nd substantially nd extend in opr t t u b m w H X .l e S m m m m aw i P m D. H 6 h t mm a E d E em mm t .mh m SC .I a a W-C $0 on MW "0 e O Sh m w uu .mdflPD.

261/94 B0lf3/04 261/94-98 "N F g m H G.m n m M r n U n mTm 5 mm PS mmm mm m a o W O4 -Mk T UIF M H M U UUU the height of the turrets above the platform a [56] References Clted posite directions from the turrets on the same side of the plat- UNITED STATES PATENT form. The platform has 0 7/1952 Cannon in th are penings to the turrets and to the slots e vanes. The hollow turrets are slotted lon gitudinally and of truncated conical form based on Preferably, there is a pair of such turrets extend' the platform.

26l/95 mg :way from zen/94 each side of the platform with an interconnecting vane joining each pair of turrets in the center of the unit on each side of the pposite sides of the middle of FOREIGN PATENTS 229,999 l/l909 Germany...................... 768,316 2/1957 Great Britain................

OTHER REFERENCES Kontak," Publication of Saran Lined Pi Mich. July 26, 1966.

platform. These vanes rise from o the platform and lie in planes which contain the longitudinal axis ofthe unit and lie at right angles to each other.

, Ferndale,

pe Co.

PATENTEDNUV 9 Ian 3,618,910

SHEET 1 BF 2 PATENTEUunv 9 |97| SHEET 2 OF 2 TOWER PACKING BACKGROUND OF THE INVENTION The present invention relates to packing for towers, columns and the like and, more particularly, to a tower packing unit of novel shape for enabling and promoting intimate surface contact between a' vapor or gas and aliquid.

In many industrial applications, it is necessary to provide means having a relatively large surface area for facilitating contact between a vapor or gas and a liquid. Surface area can berelated for example, to the volume of a tower or the packing part thereof. The greater the surface area, the more liquid is exposed to a gas, thereby improving the absorption of the gas or vapor by the liquid and/or the mass transfer between the liquid and gas.

For example, such an operation may be carried out in fractionating or distilling towers, scrubbing or washing columns, as well as in reaction, heat exchange, and absorption chambers. All of such applications and apparatus are herein generically contemplated by the term tower.

Various gas-liquid contact devices, commonly referred to as "packing, have been used for this purpose. Among the more widely used packing shapes for gas-liquid towers have'been Raschig rings and Berl saddles. In general, for efficient operation, a tower packing bed or mass should distribute a descending liquid phase and a rising, vapor phase uniformly across and throughout the width of the bed in the tower free of channeling, while simultaneously efi'ecting sufficient turbulence and intermixing of the liquid and gas phases to obtain intimate contact. It is also desirable to avoid obstructing the countercurrent flow deleteriously and employ a minimum pressure drop longitudinally of the flow. Channeling can occur when packing settles in the bed in such a way that a gas and a liquid, flowing countercurrently, tend to become segregated into areas of least and most resistance to flow. Maldistribution of gas and liquid flows reduces the efficiency of the mass transfer.

Similarly, tower packing should exhibit sufficient porosity to avoid flooding of the bed in liquid and to resist disruption or disturbance of the bed by high velocity gas flow which could blow packing units out of the tower. A related chief drawback of some prior tower packing units is their tendency to nest together adversely, even though randomly packed with care within the tower. Harmful nesting can occur when adjacent tower packing units have sufficient surface areas mutually exposed in such a manner that they fail to function as absorbing surfaces. Adverse nesting can also occur among complimentary or repetitive shapes, such as Berl saddles, hemispheres, flat faces etc. Even when such units are randomly packed within a tower, they tend to settle together or become interstacked when resting on top of each other or after having been jostled in a high velocity stream. This leads to loss of effective surface area, high pressure drops, flooding, and the like, all contributing to low mass transfer efficiency.

Because of the volume of the bed often required to be filled with packing, it is desirable that the packingunit be inexpensive, easy to manufacture, convenient to handle and replace and of light weight, while still sufficientlytough, strong and/or rigid, to be self-sustaining even when supporting many like units.

SUMMARY OF THE INVENTION The tower packing unit of my invention has a novel, multidimensional configuration in a three-dimensional envelope affording a large surface contact area, per unit of gross volume, and is preferably molded from strong, lightweight plastic. In my preferred form, the packing unit comprises a thin, central undulating platform presenting longitudinally opposite saddle-shapes at right angles to each other about the longitudinal axis of the unit. The platform is generally circular in plan view and has four major openings and a pair of hollow turrets on each side of the platform extending longitudinally away from the platform at two of the openings on each side of the platform. The pair of turrets on one side stand at right angles to the pair on the other. One of each pair of the turrets rises from the hip" part of the saddle, the other from the "thigh part, as seen from the horsemans point of view. The hollow turrets are longitudinally slotted and each has a slotted buttress vane reaching radially away from each turret and extending to substantially the periphery of the platform in a direction opposite the other vane of the pair. A central upstanding vane joins the pair of turrets on each side of the platform. The turrets taper inwardly from broad bases at the platform, to smaller tops remote therefrom. The platform may also have circumferentially extending ribs staggered on opposite sides and edges of the platform. The essential envelope for each unit is a substantially right, circular, cylindrical space with the tops of the turrets and vanes lying in the ends of the cylinder and the peripheral edge of the saddle platform undulating around, and a bit without, the waist of the cylinder.

BRIEF DESCRIPTION OF THE DRAWINGS DESCRIPTION OF THE PREFERRED EMBODIMENT My tower packing unit comprises a relatively thin-walled, saddle-shaped platfonn 10 having, as viewed from above, equal and diametrically opposite, upturned saddlebow's" and cantles l3 and 14 (FIG. 3) with equal and diametrically opposite, downtumed saddle flaps" 11 and 12 at right angles to the diametric'line of the saddle bows and cantles. As viewed from below, the parts of the platform which appeared as flaps 11 and 12 from above, appear as saddlebows and cantles 11 and I2, and the parts of the platform which appeared as saddlebows and cantles viewed from above, become flaps l3 and 14. The peripheral edge 9 of the saddle-platform 10 appears circular in plan view, FIGS. 2 and 4, and lies in a cylinder, the axis of which is the central axis a-a of the whole structure. The edge 9 takes a double, compound, sinusoidal form incident to the saddle characteristic of my saddle-platform 10.

The platform 10 has four equal circular openings 15 (FIG. 4) generally spaced in the hip and thigh" quadrants of the saddle. Each turret 15-19 stands substantially concentrically from and about each opening 15. Turrets l6 and l 7"extend from diametrically opposite openings on one side of the platform 10, and turrets 18 and 19 extend from the other two diametrically opposite openings on the other side of the platform. Each turret tapers inwardly in a direction away from the platform 10 and has longitudinally extending slots 21, four of such slots being shown in the drawings for each turret. The diametric vertical plane b-b, FIG. 2, passes throughthe axis a-a and the highest points of the upwardly turnedffsaddlebows" and cantles" l3 and 14. The plane of the longitudinal axes of the turrets l6 and 17 intersects the plane b-b in the axis a-a at the angle C of about 45. The turrets l8 and 19 on the opposite side of the platform 10 are diametrically aligned at right angles to the plane of the axes of the turrets I6 and 17, FIGS. 2 and 4. From the point of view of an imagined horseman seated in the saddle (absent the turrets and vanes) and facing the saddlebow 13, it is convenient to visualize the turret 16, FIGS. 1 and 2, in the rider's right thigh" position and the turret 17 in the place of his left hip. As shown in H08. 1 and 3 this hip and thigh disposition of the turrets puts the bases of all of them in approximately the central plane of the unit which is normal to the axis a-a. It also disposes the turret buttress vanes 25 and 26 to reach from the low points of the saddle flaps 11 and 12, as viewed from above, all the way up" to the open tops of the turrets. Since the packing unit is equal and symmetrically oppositely turned 90 upside down, the buttress vanes 27 and 28 below, as viewed, support the saddlebows and cantles above, as viewed.

The central vane 22 joins turrets l6 and 17 integrally, and a like vane 23 joins turrets l8 and 19. Each central vane extends the full height of each turret and is formed integrally with the platform 10. The central vane 22 stands at right angles to the vane 23, FIG. 2. The outer end of each vane is preferably curved convexly as at 24, FIGS. 1 and 3.

Nesting of one unit with another endwise, in view of the open, tapering, tubular nature of the turrets is inhibited by the vanes attached thereto. Vanes 25 and 26 extend full-height from the open tops of the turrets l6 and 17, respectively, in opposite but parallel directions, as do vanes 27 and 28 from turrets l8 and 19 in opposite but parallel directions. Each of these vanes lie in a chordal plane of the geometric cylinder defined by the sinuous edge of the platform. The vanes on each side of the platform are directed substantially at right angles their opposite numbers" on the other side, as well as at right angles to the central webs 23 and 24, respectively on the same side. Sidewise nesting," more accurately juxtaposition, is turned to advantage and enhances absorption area per cubic feet of volume. For example, a lower turret with its buttress vane of one unit may intrude, as into the right foreground of FIG. 1, toward a pair of upper turrets and their central vane of another unit, above the saddle platform of the latter, but such intrusion will be substantially limited to a point, or small line, contact between the units. Moreover, such an intrusion with the small open end of the intruding turret generally near and spaced above the large open end of a lower turret, as above the turret 18 in FIG. 1 effects reduced volume for the packing bed without appreciable loss of operative transfer area and without impairing free flow and counterflow of gas and liquid through the juxtaposed units.

Preferably, all buttress vanes have longitudinally disposed slots 30 and the platform 10 has openings 31 communicating with each slot. The diameters of the openings 31 preferably correspond essentially to the widths of the slots 30 and are less than the diameters of the turret openings 15. Circumferentially extending reinforcing ribs 32 are formed integrally with the platform 10 along its rim. Preferably, the ribs have a length of approximately one-fourth of the circumference of the platform 10 and are staggered in sequence on opposite sides of the platform as illustrated in FIGS. 2 and 4.

My tower packing unit can be made from many appropriate metallic, ceramic, resinous and plastic materials in a convenient range of sizes. Present experience suggests the desirability of making the units about three inches in diameter as viewed in FIGS. 2 and 4. Similar advantages are contemplated for units about half the size, Substantially the only limitations on the choice of a material for my packing unit are cost, resistance to attack by fluids to be contacted, and facility to be shaped into the desired form. A desirable material is a moldable, strong, relatively lightweight synthetic plastic or resin, such as polyethylene, the various polyvinyl resins like polyvinyl chloride, polyvinyl acetate, polyvinyl alcohol and the like, polyamides like nylon, polytetrafluorethylene, etc. A preferred synthetic resin is polypropylene. When the packing unit is capable of being fabricated from a moldable plastic, it can be made in a single die of two mating parts.

ln use, a plurality of the packing units are dumped at random in bulk into a tower or the bed part thereof and haphazardly arranged whereby the units increase the internal surface of the tower and facilitate the intimate mixing of descending and ascending fluid streams passing through the tower. My invention improves the performance and efficiency of mass transfer and permits high velocity fluid movement through the packing bed.

It will be noted that the present tower packing unit is devoid of pockets and projections which tend to collect dirt, impurities, and the like. Such dirt or impurities often build up to a point of eventually plugging or blinding the packing. The freeflowing, self-cleaning feature afforded by the present packing unit provides for longer operating periods before interrupting the operation to inspect and clean the tower.

The novel design of the present unit provided a 30 percent reduction in the number of units needed per cubic foot of bed or tower volume. My invention also results in a lower energy loss in the total system. All of the described advantages of present unit contribute to an increase in the absorption of gas by a liquid or a stripping of a gas from the liquid.

While the foregoing has described a presently preferred embodiment of my invention, 1 do not want to be limited thereto in the scope and effect of my patent, nor limited in any other manner inconsistent with progress by which the art has been promoted by my invention.

1 claim:

1. A packing unit comprising a generally circular saddleshaped platform having openings and having two hollow, open-ended projections extending substantially concentrically from two of the openings from one side of the platform, two similar hollow projections extending substantially concentrically from two other openings and from the opposite side of the platform, said hollow projections being joined by a central vane on each side of said platform, and each projection having a buttress vane connecting a side of a projection to said platform.

2. A tower packing unit comprising a perforated saddleshaped platform, a pair of hollow, turretlike projections of substantial height extending from the platform adjacent openings, and a central vane joining the projections.

3. The packing unit of claim 2 wherein at least one of said projections has a laterally extending buttress vane engaging said platform.

4. The packing unit of claim 3 wherein said vane is slotted adjacent an opening in said platform.

5. The packing unit of claim 3 wherein said buttress vane is slotted and the slot of the vane communicates with an opening in said platform.

6. The packing unit of claim 2 having a like pair of said projections disposed on the opposed side of said platform.

7. The packing unit of claim 6 wherein said like pair of projections are joined by a like central vane on the said opposite side of said platform, said vanes being axially opposite and circumferentially angled with respect to each other.

8. A tower packing unit comprising a central platform with a pair of turrets of substantial height rising from each side of the platform, said turrets being hollow and said platform having openings that are unobstructed on one side but open to and substantially concentric with the interiors of the turrets on the other side of the platform.

9. The packing unit of claim 8 with buttress vanes integrally attached to said turrets and to said platform, said platform having holes opening to said vanes.

10. The packing unit of claim 9 wherein said platform is undulating and said turrets are joined to said platform in approximately a plane normal to a perpendicular central axis passing through said platfonn.

11. The packing unit of claim 10 in which said pairs or turrets are diametrically aligned on each side of said platform and each pair is turned at right angles to the other on opposite sides of said platform.

12. The packing unit of claim 11 wherein each pair of said turrets on the same side of said platfomi are joined full height by a central vane embracing the axis of said unit.

13. The packing unit of claim 12 in which said platform is substantially round as viewed in the direction of its axis and has a diameter, so viewed, about as long as the length of the unit measured along said axis.

14. The unit of claim 13 in which said platform is saddleshaped and the turrets of each pair on one side are disposed at the hip" and thigh parts of the saddle and the buttress vanes extend oppositely to the lowermost parts of the edge of the saddle on one side and support the saddlebow and cantle" parts of the saddle on the other side. 

1. A packing unit comprising a generally circular saddle-shaped platform having openings and having two hollow, open-ended projections extending substantially concentrically from two of the openings from one side of the platform, two similar hollow projections extending substantially concentrically from two other openings and from the opposite side of the platform, said hollow projections being joined by a central vane on each side of said platform, and each projection having a buttress vane connecting a side of a projection to said platform.
 2. A tower packing unit comprising a perforated saddle-shaped platform, a pair of hollOw, turretlike projections of substantial height extending from the platform adjacent openings, and a central vane joining the projections.
 3. The packing unit of claim 2 wherein at least one of said projections has a laterally extending buttress vane engaging said platform.
 4. The packing unit of claim 3 wherein said vane is slotted adjacent an opening in said platform.
 5. The packing unit of claim 3 wherein said buttress vane is slotted and the slot of the vane communicates with an opening in said platform.
 6. The packing unit of claim 2 having a like pair of said projections disposed on the opposed side of said platform.
 7. The packing unit of claim 6 wherein said like pair of projections are joined by a like central vane on the said opposite side of said platform, said vanes being axially opposite and circumferentially angled with respect to each other.
 8. A tower packing unit comprising a central platform with a pair of turrets of substantial height rising from each side of the platform, said turrets being hollow and said platform having openings that are unobstructed on one side but open to and substantially concentric with the interiors of the turrets on the other side of the platform.
 9. The packing unit of claim 8 with buttress vanes integrally attached to said turrets and to said platform, said platform having holes opening to said vanes.
 10. The packing unit of claim 9 wherein said platform is undulating and said turrets are joined to said platform in approximately a plane normal to a perpendicular central axis passing through said platform.
 11. The packing unit of claim 10 in which said pairs or turrets are diametrically aligned on each side of said platform and each pair is turned at right angles to the other on opposite sides of said platform.
 12. The packing unit of claim 11 wherein each pair of said turrets on the same side of said platform are joined full height by a central vane embracing the axis of said unit.
 13. The packing unit of claim 12 in which said platform is substantially round as viewed in the direction of its axis and has a diameter, so viewed, about as long as the length of the unit measured along said axis.
 14. The unit of claim 13 in which said platform is saddle-shaped and the turrets of each pair on one side are disposed at the ''''hip'''' and ''''thigh'''' parts of the saddle and the buttress vanes extend oppositely to the lowermost parts of the edge of the saddle on one side and support the ''''saddlebow'''' and ''''cantle'''' parts of the saddle on the other side. 